Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations only declare it is a non-readOnly, open-world, non-destructive write. The description goes well beyond that, disclosing real side effects ('the entry goes straight into the books'), the debit=credit constraint, the confirmation requirement and its opt-out, the outbound/people-reaching nature, and the API key prerequisite.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The duplicate opening sentence is wasted text, and the 'Bokio:' prefix repeats the title. The confirmation and API key notes are useful but appended in a somewhat run-on sequence rather than front-loaded priorities.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a mutation tool with no output schema but full annotation and parameter coverage, it supplies the safety profile, side-effect permanence, confirmation policy, and prerequisites an agent needs. Missing only explicit guidance on entry correction/immutability after posting.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

With 100% schema coverage the baseline is 3, but the description adds meaning beyond the schema by stating the balance rule, that only Bokio-supported accounts are accepted, and that accounts should be fetched via list_accounts. That said, it does not clarify the expected structure of the 'items' rows beyond what the schema already documents.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb+resource ('Book a manual journal entry') and clearly distinguishes it from the sibling bokio_list_journal_entries. It loses a point only because the first two sentences redundantly restate the same action ('Book a manual journal entry with a title, date and balanced rows. Books a manual journal entry.').

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Routes the agent to a sibling for a prerequisite ('only accounts Bokio supports are accepted; look them up with list_accounts') and explains the confirmation default/override. It stops short of explicitly stating when to prefer this over other Bokio tools or when not to use it.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.